The invention relates to a drafting unit for a spinning machine having several over-mounted bottom rollers which are each assigned to a spinning point and which are in driving connection with drive shafts extending through in the longitudinal direction of the machine.
In a known construction of the initially mentioned type (JP-A 62-69832), a common housing is provided for two adjacent drafting units respectively which encloses the driving connection of all bottom rollers of these two drafting units. The drive shafts are disposed in this housing. The bottom rollers each have bearing housings by means of which they are detachably arranged in the common housing. Although, in the case of this construction, the bottom rollers can be demounted relatively easily together with their bearings, a servicing of the other elements is connected with considerable mounting expenditures, in which case it is also necessary to stop the whole spinning machine during servicing work at one spinning point.
An object of the invention is to develop drafting unit of the initially mentioned type such that servicing operations are easier to carry out.
This object is achieved in that the bottom rollers are held by components which are detachably mounted at a machine frame which accommodates the drive shafts.
As a result of this development, it is possible to demount and remount one or several bottom rollers of a spinning point with the pertaining structural elements without interfering with the operation of the adjacent drafting units.
In a further development of preferred embodiments the invention, it is provided that the bottom rollers are each, fastened to a component by means of their own holding device. In this case, it is expedient for the bottom rollers to each be disposed on shafts and to be connected with the pertaining drive shaft by way of a toothed-wheel drive containing a shiftable coupling. In particular, if the coupling and a pertaining toothed wheel are arranged coaxially with respect to the bottom roller and are therefore also held by the holding device of the respective bottom roller, when a bottom roller is demounted, the coupling is at the same time also demounted together with it, so that it can then be examined.
In a further development of preferred embodiments of the invention, it is provided that the bottom rollers of one spinning point are held at one support respectively which extends transversely with respect to the longitudinal direction of the machine and which is mounted at the machine frame. As a result, by means of simple mounting work, such as soldering or remounting of the support, it may be achieved that all bottom rollers of a drafting unit are removed or remounted simultaneously. In a further development of this embodiment, it is provided that the supports accommodating the bottom rollers of two adjacent spinning points are constructed as a frame by means of struts extending in longitudinal direction of the machine. As a result, the bottom rollers of two adjacent spinning points are combined to a structural unit which can be mounted or demounted as such. In a particularly expedient development, it is provided in this case that one of the struts is constructed as a supporting rod on which a carrying and loading arm is pivotably disposed. This carrying and loading arm accommodates the top rollers of the two adjacent drafting units so that, as a result, these two adjacent drafting units can be mounted and demounted as a complete structural unit, only the drive shafts remaining at the machine. The demounting or the mounting is not hindered by the drive shafts remaining in the machine frame so that this work can take place without stopping the spinning machine. At least it is ensured that the machine can continue to run also after the demounting of the adjacent drafting units constructed as a subassembly. The reason is that the bearing of the drive shafts is not affected.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.